The present invention relates to the operation of dual-mode phones, and more particularly, to handling voicemail in dual-mode phones.
Dual-mode phones support connections via Wi-Fi and cellular networks. In an enterprise environment, calls placed to phone numbers associated with the enterprise are sent from the enterprise SIP PBX to a mobility controller. The mobility controller then attempts to forward the incoming call through the enterprise Wi-Fi network to the proper dual-mode phone. If the desired dual-mode phone is not available on the enterprise Wi-Fi network, the mobility controller establishes a call through the SIP PBX to the cellular side of the desired dual-mode phone.
A problem arises however, as the enterprise provides a voicemail system to enterprise users, but when a call is forwarded by the enterprise mobility controller to the cellular side of a dual-mode phone, the enterprise user no longer has any indication of whether or not voicemail has been left with the separate cellular network; the enterprise and cellular voicemail systems are separate.